Demand register



Oct; 14, 1941.

R. H. LEWIS ETAL 2,259,314

DEMAND REGISTER Filed July l, 1958 flax/'m am demana//aa/hlers WITNESSES:

INV NTOR5 Patented Oct. 14, 1941 DEMAND REGISTER Robert H. Lewis, North Arlington, and Paul G.

Adams, Bloomleld, N. J., assignors to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsyl- Vania.

Application July 1, 1938, Serial No. 217,024

22 Claims. (Cl. 171-34) This invention relates to registers and it has particular relation to reset mechanisms for registers of the maximum demand type.

In Patent No. 2,047,376 to Lewis et al., a maximum demand meter of the indicating type is disclosed. Meters of this type have an indicating member which is actuated during a billing period, usually one month, to a position corresponding to the maximum demand for the billing period. At the end of the billing period, it is customary to note the quantity indicated after which the indicating hand is manually returned to an initial or zero position. This procedure is open to several objections. Once the indicating hand has been restored to its initial position, all record of the maximum demand for that particular period is lost, and no check is available on the person who has noted such maximum demand. Moreover, on most manual resets of this type, it is possible for the indicating hand to be reset to a position other than the zero position.

The diiliculties experienced with meters of the type shown in the aforesaid patent may be overcome by providing an independent register for the maximum demand reading. Such a register would have an amount added thereto for each billing period corresponding to the maximum demand for that billing period. In order to eliminate possible inaccuracies from the manual reset of the register, it is preferable to provide a motordriven reset which may be actuated periodically at the end of each billing period. Since meters to which maximum demand registers ordinarily are applied have little power available for driving the register, and since such registers must be capable of long service without attention, some ingenuity is required in the design of a suitable register.

In accordance with our invention, a separate maximum demand or cumulative register is provided which is actuated once at the end of each billing period to preserve the maximum demand for that period. This register is actuated by motive means which is coupled and uncoupled thereto by means of gears. This avoids the inaccuracies and power demands of clutches.

It is, therefore, an object of our invention to provide a simple and reliable register having a motor reset attachment.

It is a further object of our invention to provide a cumulative type of maximum demand register wherein gears are employed for coupling and uncoupling a reset motor thereto. It is a further object of our invention to provide a reset device for transferring a demand indication to a register which cannot be actuated when no demand indication is available for transferto the register.

Itis a further object of our invention to provide an interval clutch for a demand register which has a positive release.

It is a still further object of our invention to provide a demand register with a clutch having a uniform slip resistance when engaged.

Further objects of our invention will be apparent from the following description taken in ccnjunction with the accompanying drawing, in which:

Figure 1 is a view in perspective of a register embodying our invention;

Figs. 2 and 3 are exploded perspective views Y showing two positions of the control levers em- Cla ployed for resetting our register;

Fig. 3a is a detail view in perspective showing a spring construction for a reset latching lever.

Fig. 4 is a detail View partly in cross-section of a maximum demand indicating assembly; and

Fig. 5 is a detail view showing the gear coupling between the maximum demand indicator and the register.

Referring to the drawing, the register shown in Fig. 1 is based very largely on that shown in the aforesaid patent. For convenience, the parts shown in Fig. l which correspond to those disclosed in the aforesaid patent are provided with similar reference characters. Briey, the register illustrated comprises a disc 2 of an induction watthour meter which drives indicating pointers 8 through a shaft 3, worm gear and worm wheel 5, and a suitable gear train 6. The integrating pointers 8 may be employed for indicating kilowatt-hours on dials formed on a face plate I0 in a customary manner.

In order to indicate the maximum demand for a, billing period, a pusher arm 20 is attached to a sleeve 22, which is periodically rotated. The sleeve 22 and a gear 24 are mounted on a shaft 25 and constitute parts of a releasable clutch. The gear 24 is driven from the disc 2 by means of a gear 26 which is coupled to the disc 2 through the gear train 6. At periodic intervals, usually every thirty minutes, the clutch is released to free the sleeve 22, which is returned to an initial or zero setting by means of a spiral spring 28 which has one end attached to the sleeve 22 and the remaining end attached to a stationary part of the register. Consequently, the maximum rotation of the sleeve 22 and the pusher arm 20 carried thereby represents the maximum demand for a thirty-minute period.

The release of the clutch after each demand interval is eiected by means of a clutch release lever 44 which rocks on opposed pivots 45 (only one of which is shown). In order to time the actuation of the lever 44, a constant speed motor 50 is provided which may conveniently be of the hysteresis type. This motor, through a suitable enclosed speed reducing gearing 52, drives a shai't 511 which may rotate, for example, at one revolution per minute, and which, through gearing 58, rotates a shaft 60 and a sleeve 10 at different rates. For example, if a thirty-minute period is employed, the shaft 60 may be rotated one revolution each thirty minutes, and the sleeve E may be rotating twelve times as. rapidly.y At its lower end, the shaft SEI carries a disc 62 on which a cam lever 54 is pivotally mounted. A cam disc 'I2 is mounted on the sleeve 10 adjacent the cam lever 64. Once during each revolution of the disc 52 the actuating portion of the cam lever. is adjacent .the clutch. release lever M. At this moment, the high portion. of the cam..'|2 strikes the actuating portion ofthe cam lever E0 .and moves it sharply against the clutch releaselever'lto release the clutch for a` short interval merely sufficient to. permit the. return of thesleevel 22 and pusher arm 20 to. their initial positions.l For test.v purposes, .an overrunning clutch 9...preierably is.. included between the motor and the clutch release assembly. Further details of. the construction. thus. far described Will-be lfound by reference to the aforesaid patent.

In order to preserve an indication of the maximum. position. to which .the pusher arm 20. is rotated in a thirty-minute. interval, a sleeve |00 is lmounted freely. onthe shaft 25 in coaxial alignment with the sleeve 22. The sleeve |00. carries an arm |0I provided with a pin |02 in the path of movement of the pusher arm. 20. As the pusher. arm 20- rotates, it.engages the pin |02 and carries. the sleeve |00 withv it. The sleeve |00iis provided also Withagear |03-vvhich prefer.- ably carries an. indicating. pin |04. Thisv indicating pin projects through an opening |05 in the register face I0, the opening being shown in dotted lines.. in Fig. 1. Consequently, as the pusher arm rotates, the pin Ilwill be carried to a .positioncorresponding to the maximum rotation of the pusher arm. If desired, a scale may be .provided .on the register face I0 for inydicatingthe demand corresponding to any' movementlofthe pin IM. When the 'pusher Yarm 20 returns toits initial or Zero positionv at the end of one of its thirty-minute intervals, the pin |04 remains inl the positionxto which. it has been rotated, and over a billing period, say, a thirtyday period, indicates the maximum thirty-.minute demand for the billing period.

lfthe pin |04. were returned to an initial or zero position at the end of a billing period, no record. ordinarily would remain of the position from which. it. was moved.. In orderto provide such a record, we include in o ur register a second setY of integratingpointers |06 which may be similar to those 8 employed for indicating kilowatt-hours. At the end of each billing period, the, integrating pointers |06 are coupled to the pin|0| and are advanced in accordance With the resetting movement of the` pin by a mechanism which now will be described.

As above noted, the pin |04 is carried on a gear |03. This gear meshes with another gear |01 which is fixedto a sha-ft |00. Fixed on theA shaft I08iis a. gearfl09.l which meshes with a gear H0 (Fig. 5) carried by a sleeve 1| II, the sleeve being free to rotate on a shaft ||2. The sleeve III also carries a gear H3. A second sleeve ||4 on the same shaft I|2 carries two gears I I5 and IIB thereon. The gears ||3 and I|5 are adjacent each other and are of the same size. The gear H6 is connected through a gear to the first shaft ||8 of the maximum demand integrating pointer unit.

It will be noted that the gear ||3 moves in accordance with movements of the pin |04, whereas the gear ||5 moves in accordance with movements of the integrating pointers |00. Immediately prior to the resetting of the pin |04 and its associated mechanism at the end of a billing period, these two gears II3 and |I5 are coupled by meansof an elongated pinion ||9 which is moved vinto engagement therewith. As a result of this. movement, the pin Illl, through the gears |03, |01, |09, |I0, IIS, H0, ||5 and IIB, is coupled to the integrating pointers |06, and any movementthereof is transmittedto the integrating pointers. and retained thereby. At the end of thereset operation, thev pinion |.I91 is moved. out of. engagement. with its. associated gearsr While. the .foregoing operations could be car.-

ried outmanually, itis preferable. to provide an automatick reset. and.v to. drive. the reset. mechanism fromA the. timing motor 50. For this. purpose, a crown gear. |20. is coupled tothe motor 5e: through suitable, gears. |2.|. and |22 andone ofthe gears of the. gear .train 58 which is connected tothe motor 50., through. the gearing 52'. During a resetting.operation,.this crown gear is connectedto the. integrating. pointers. 05. andthe indicating. pin ld-through gears. |23 and. |24, whichA are. xed on a common shaft. |25. The gear |26. meshes withy a gear, |25, which isilxed to the. shaft |08, and which through the shaft rotatesthe gears. |011, and |09. 'Ihese gears. in turn communicate movementv to the indicating pin |04.and the integrating. pointers |06..

- Ifthe gear |23 were coupled tothe crown gear |20 beforethe pinion ||9 were moved into engagement with its associated gears, movement would* be transmitted. to the indicating pin |04 before .movement could be transmitted tothe integratingpointers |05; This would result .in an inaccuracy inV the amount. indicated by the. irltegrating pointers. Since. it is rather diicult to assureasimultaneous engagement of two couplingmeans, we .prefer to. effect an engagement of .the pinion. H9 rwith its, associated gears .prior to the engagement of thegear. I 23 with the crown gear |20.-` .Such a sequence.- of operations.v can producano errorin the. amounts depicted by. the register, and is obtained. by. a system of. levers which now will be described.

Referringmore particularly yto FigsZ, 3 and. 5, the-pinion IIS. is mounted on a lever |21, which inturn Yrotates on a shaft |20. Movement of the pinion. iscontrolled by a lever |29 which carries; a pin |30 that projects into a. relatively large recess. |3 .in the headof a pinion mountingbolt |32 (Fig. 5.). A coil spring |33 surrounds the shaftv |28 .and has one arm engaging thebolt |32 and a second arm engaging the head of the pin. |30 Afor biasing. the pinion I|0in a counter-clockwise direction,` as. shown in Figs. Zand 3, Movement of the lever |29 isv controlled in turn partly through a slotted lever |34which lis pivotally mounted ona screw .I 35 which passes through. a boss |55 Vprovided on the lever |29., The, slotted lever |341 carries atits pivot point aproiecton |37, about which a coil spring ls wrapped. One arm |38 of the coil spring engages a pin |39 attached to the slotted lever, and the other arm |40 of the spring engages the lower side of the shaft |28 Vand rests on a stationary lug |4|. Two biasing actions are produced by this spring. The arm |38 tends to rotate the slotted lever 34 in a counter-clockwise direction, as shown in Figs. 2 and 3, until an extension of the pin |39 engages therupper surface of the lever |29. The long arm |40 of the spring acting through the projection |31 and the boss |36 tends to rotate the lever |29 in a clockwise direction, as shown in Figs. 2 and 3.

Actuation of the gear |23 also is effected through the slotted lever |34. For this purpose the slotted end f the lever |34 engages a pin |42 carried by an arm |43 fixed to a shaft |44 that carries a floating bearing |45 for the shaft |25. It should be noted that rotation of the shaft |44 rocks the bearing |45 to withdraw the gear |23 from the crown gear |20 or to engagesaid gears. In this way, the motor may be connected to the reset Ymechanism and may be disconnected therefrom. A stop pin |46 may be provided for cooperation with a stationary part of the register (not shown) for adjusting the movement of the gear |23 into contact with the crown gear |20. Movement of the arm |43 is restricted by means of a stop |41 which may be formed in the register face I0, if desired, and which engages a projection of the pin |42.

For actuating the levers thus far described, we provide a relatively rigid coil spring |48 which surrounds a screw |49 that is threaded into a tapped recess |50 provided in a stationary member The stationary member also carries an adjustable pin |52 for providing an adjustable stop for the lever |21. The spring |48 has one arm positioned in a recess |53 provided in a push rod |54 while the other arm of the spring |48 bears against the slotted lever |34, as shown more clearly in Fig. 5. Consequently the coil spring constitutes a resilient bell crank connecting the slotted lever and the push rod |54.

When the push rod |54 is depressed inwardly, as shown in Fig. 2, the spring |48 tends to move the slotted lever |34 in a clockwise direction. Since the pin |42 in this figure is against its stop |41, the slotted lever |34 rotates about this pin as an aXis and, therefore, rotates the lever |29 in a counter-clockwise direction. The counterclockwise rotation of the lever |29 carries the pinion ||9 into engagement with its associated gears ||3 and ||5, this engagement being somewhat resilient because of the action of the spring |33. The lever |29 is provided with two pins |55 and |56 which form a pocket adjacent the tip of the lever. The pin |56 may be conveniently formed by bending a lug on a plate |51 and passing the lug through an opening in the lever |29, the plate |51 and lever |29 being united by a rivet or by other suitable means. When the lever |29 is rotated as a result of the depression of the rod |54, the pin |56 is carried past the tip-of a biased latching lever |58 which thereupon drops into the pocket formed by the pins |55 and |56V and holds the lever latched against return. The latching lever |58 conveniently may be biased by means of a weight |59, as shown, or by a spring and is-rnounted for rotation on a shaft |60. Normally, as shown in Fig. 1, the pins |56 and |55 are positioned within a recess |6| provided in the latching lever |53, but, as stated, rotation of the lever |29 carries the pin |56 past the latching edge of the latching lever |58 which operates to hold the pinion ||9 in engagement with its associated gears.

When the actuating rod |54 is released, the parts take the position shown in Fig. 3. Because of the action of the latching lever |58, the spring arm |40 cannot return the lever |29 to its original position. The spring arm |38, however, tends to return the slotted lever |34 towards its original position, .but because the boss |36 about which this lever rotates has shifted, the slotted lever moves the arm |43 and shaft |44 in a clockwise direction and this movement brings the gear |23 into contact with the crown gear |20. Consequently, the integrating pointers |66 are connected to the demand indicating pin |04 and to the motor 50 which rotates the indicating pin toward its initial or zero position and simultaneously sets up on the integrating pointers an increased reading corresponding lto the return movement of the indicating pin |04.

` In this return movement of the indicating pin,

the sleeve |30 and arm |0| also are returned, and the pin |02 engages the pusher arm 20, if the latter is in an advanced position, and carries it to the Zero position against the friction of the clutch. An adjustable stop |62 may be provided for determining the Zero position.

As the arm |0| rotates in its return movement, it engages a pin |63 provided on the latching lever |58, and in the zero position rotates the latching lever suiciently to free the lever |29. The lever |29 is promptly returned to its original position by means of the spring arm |40, and this movement not only moves the pinion ||9 away from its associated gears, but through the slotted lever |34 carries the pin |42 against its stop |41. Since the displacement of the pin 42 is transmitted through the arm |43 and the shaft |44 to the bearing |45, the resultant rotation of the bearing carries the gear |23 out of engagement with the crown gear |20. Consequently, the mechanism is restored to its original condition.

If desired, one or more friction pads may be mounted on any of the shaft to resist undue movement thereof. As illustrated, the shaft |08 and I8 are provided with discs |64 against which felt or other friction pads |65 are urged by means of leaf springs |66. The tension of the springs may be adjusted, if desired, by means of screws |61 which are threaded through stationary parts of the register.

Occasionally the push rod |54 may be depressed when the indicating pin |04 is at or near its zero position with a possible latching of the lever |29 in its reset position. To forestall such a possibility, we prefer to bias the latching lever |58 away from the lever |29 when the indicating pin is in its initial or zero position. This may be accomplished, for example, by mounting a leaf spring on either of the levers |0| or |58. As illustrated in Figs. 2 and 3, a leaf spring |68 is secured to a pin |69 which is mounted on the lever |58. The free end of the spring normally is positioned slightly above the pin |63. During a resetting operation, as the arm |0| approaches its zero position it depresses the spring |68 against the pin |63 and releases the latching lever |58. After the release of the latching lever the spring |68 maintains the lever in its released position until the arm |0| clears the spring by rotating slightly in a clockwise direction. Therefore the resetting mechanism is ineffective when the indicating pin |04 is in its zero or initial position. If desired the spring maybe loopedaround the pin |63 which is notched as shown in Fig. 3a. The lipr on the spring engages the pin for restricting the movement of the spring to any desired amount.

Itis believed that the operation of the aboved'escribedvapparatus is apparent. The gearing which drives the cam devices |54Y and l2 is selected to provide any desired maximum demand interval which may be ten, thirty or sixty minutes. Over the billing period, the pin |04- is then advanced to a position corresponding to the maximum demand for any of these intervals. When the billing period has expired, this being usually of a months duration, a meter reader will note the reading of the integrating pointers |06 and thereafter depress and release the actuating rod |54. Following such depression and release, the mechanism as above described returns the pin |04, arm lill, and pusher arm 20 to their initial or Zero positions and the mechanism is thereupon available for another billing period. By subtracting the first reading of the integratingpointers from the new reading, the diierence or maximum demand for the billing period is obtained.

If the register is enclosed within a sealed casing, a seal may be provided over the actuating rod |54 so that the operation of the actuating rod can be effected only by an authorizedperson.V If desired, a cover may be provided with a depressible plunger which, when the cover is in position, overlies the actuating rod |563 so that depression of the plunger also depresses the actuating rod. The plunger may then be provided with suitable sealing means.

Although a clutch similar to that shown in the aforesaid patent may be employed for coupl-ing the gear 24 to the sleeve 22, we prefer Vto employ-the structure shown more particularly in Fig. 4. It should be noted that the clutch performs several functions. Not only must it enga-ge positively enough for rotating the pusher arm 20 against the bias of the return spring, but it should'release completely in order to permit the employment of a weak spring 2S, and it should slip readily when engaged to facilitate the reset of the register at the end of a billing period.

In the assembly illustrated in Fig. 4, the pusher arm 20 is mounted on a hollow shaft orY sleeve 22 preferably, though not necessarily, provided with an enlargement or head 200. This enlargement is releasably engaged by a plurality of equi-spaced fingers 20 three being a suitable number, which are pivotally mounted on a ring 202l and project through elongated slots 203 formed in a driving gear 24. A hub 20d not only supports the gear 24-on the shaft 25, but is provided with slots for receiving portions of the lingers 20|. Preferably the ring 202 is a snap ring which snaps into a groove providedaround the hub 204.

Actuation of the fingers 20| is effected through a sliding collar 206 which is provided with a cam portion 201 adjacent a releasing lug 208 on each of the fingers. The collar is biased by means of a coil spring 30 against an inclined portion 209 on each linger for forcing the lingers into frictional engagement with the head or enlargement of the sleeve 22. In this position the pusher arm 20 is actuated in accordance with the rotation of the watthour meter disc 2 against the bias of Vthe spring 20. During a resetting operation, the pusher arm 20 may be actuated readily inthe reverse direction, the frictional engagement of the fingers 20| with the sleeve 22 being sufficiently small` and uniform to permit a satisfactory reset of -the mechanism.

When` the clutch release arm 111|v is actuated, the cam portion 2li-l` engages the lugs 20S-.for releasing positively the fingers 20| from the sleeve 22. Because of the complete release of the clutch fingers, the spring 28v may be made weak enough to impose no vundue burden on the Watthour meter.

In assembling the structure shown in Fig. 4, preferably the hub 204 is secured to the shaft 25, as by making the hub a press fit thereon. A shoulder 25 on the shaft 25 may be employed 'for spacing the sleeves 22 and |00. Intermediate the ends of the sleeve 22 We prefer to reduce the cross-section of the shaft 25 for providing a clearance, the sleeve being supported at its ends on portions of the shaft of larger cross-section. The ends of the shaft 25 are mounted in suitlable bearing-s.

A clutch -of the type illustrated and described is disclosed more fully in application Serial No. 159,039, iiledAugust 14, 1937.

lI'he exact construction illustrated may, of course, be varied in many particulars. For eX- ample, instead'of the integrating pointers 8 or |06, other registering mechanisms such as cyclometer dials or rotatable discs may be employed in their place. Since the maximum demand is obtainable from the pointers |06, an indicator, such as the pin |04, need not be employed. Ordlnarily it is desirable to include the indicator. Although we have illustrated a hysteresis type of motor 501, other constant speed motors or clockwork mechanisms may ybe employed as desired and separate motors may be employed for interval timing and resetting operations. The gear couplings H3, H5, ||9 and |20, |23 may be replaced by any suitable clutch units.

Since our invention is capable of many modications, we do not desire to be restricted to the specic embodiments illustrated and described. Therefore, our invention is to be restricted only by the appendedclaims as interpreted in rview of the prior art.

We claim as our invention:

1. In aninstrument, a member movable to a position corresponding to the demand measured by said instrument for a predetermined period, means for actuating said member including a releasable clutch, eleotromotive meansfor restoring said member against the resistance of said clutch to a predetermined setting, and means for restoring said member to said predetermined setting including means for releasing said clutch.

2. AIn an instrument, a member movable to a position corresponding to a quantity measured for a predetermined period, means for actuating said member including a releasable clutch, an element for actuation by said member to a position corresponding to the maximum movement of said member during a predetermined period, electromotive means for restoring said member land element to predetermined positions against friction coupling, and means for periodically releasing said friction coupling.

4. In a maximum demand indicatorreset, an indicator, an actuating member and means responsive only to both movement away from an initial position and return of said member for initiating a resetting of said indicator.

5. In an instrument, a member movable in accordance with a variable quantity, indicating 12. In a register, a maximum demand indicator, a iirst transmission member driven in accordance with said indicator, a register, a second transmission member driven in accordance with said register, a third transmission member for coupling said first and second transmission members, said third transmission member being yieldably biased in engagement with said iirst and second transmission members and movable for inmeans, a Iirst means for coupling said member l terrupting said coupling, a motive device, and tosaid indicating means, motive means, a sectransmission means between said motive device ond means for coupling said motive means to said and one of said first two transmission members, member, and means for actuating both of said said transmission means including a releasable coupling means, said means actuating said seccoupling and means operative after movement ond couplingmeans subsequent to actuation of l of said third transmission member to its engaged said iirst coupling means. position for urging said coupling into its trans- 6. In an instrument, indicating means, and mitting position.

means for actuating said indicating means in- 13. In an instrument, a control device for recluding a plurality of coupling means, a control setting said instrument to a predetermined conmember, means responsive to movement of said dition after a departure therefrom, latching control member in a first direction for actuating a first one of said coupling means, and means responsive to movement of said control member in a second direction for actuating a second one of said coupling means.

7. In an instrument, a movable member capable of remaining in a position to which it is moved, electromotive means for restoring said movable member to a predetermined position, a latch device for maintaining said electromotive means operatively connected to said movable member, said latch device being released in response to the arrival of said movable member at a predetermined position for interrupting said operative connection.

8. In a control system for an instrument, a first lever, a first releasable coupling means controlled by said first lever, a pivot carried by said first lever, said rst lever being movable into and away from a position wherein said coupling means is engaged, latching means for holding said rst lever in said position, a second lever mounted on said pivot, a second releasable coupling means controlled by said second lever, said second lever being free for engaging said second coupling means only when said rst lever is in a predetermined position.

9. In an instrument, a movable operating member, a spring having a projecting arm positioned for movement by said operating member, said spring being rotatable about an axis positioned vat an angle relative to the direction of movement of said operating member, an operated member, and a second projecting arm on said spring for operating said operated member.

10. In an instrument, an element movable in accordance with a variable quantity, register means for registering movements of said element, a iirst transmission member movable in accordance with movements of said element, a second transmission member movable in accordance with movements of said register means, and a third transmission member for coupling said first and second transmission members, said third transmission member being movable into and out of effective bridging relationship relative to said iirst and second transmission members.

11. In an indicator reset mechanism, an indicator, a iirst gear operatively connected to said indicator, a register, a second gear operatively associated with said register, said gears being mounted on parallel, aligned shafts, and separate coupling gear means rockable into and out of effective bridging relationship relative to said iirst and second gears.

means for maintaining said control device in operative position, release means for releasing said latching means after a resetting operation, and means for preventing premature movement of said laching means to latching position While said instrument is in said predetermined condition.

14. In a register reset, a member movable to a position corresponding to a variable quantity, means for restoring said member to a predetermined setting, and means for preventing actuation of said restoring means until said member has departed appreciably from said predetermined setting.

15. In a demand instrument, a member movable to a position corresponding to a variable quantity, means for resetting said member to a predetermined position, a latching lever for maintaining said resetting means in operation, said latching lever being operable by said member as it approaches said predetermined position for releasing said resetting means, and a spring element interposed between said member and said latching lever for providing a resilient engagement therebetween when said member is in its predetermined position.

16. In a maximum demand instrument having a movable member and means for moving said movable member from an initial position to a position corresponding to the maximum demand for any desired interval, a source of power, a movable lever, means controlled by the position of said lever for operatively connecting said source of power to said movable member for restoring said movable member to said initial position, latching means for holding said lever in source-connecting position, and means effective on arrival of said movable member in said initial position for tripping said latching means.

17. In a maximum demand instrument having a maximum demand cumulative register, a movable member and means for moving said movable member from an initial position to a position corresponding to the maximum demand for any desired interval, a source of power, a movable lever, means controlled by the position of said lever for operatively connecting said source of power to said movable member for restoring said movable member to said initial position and to said register for summating the maximum demands occurring between restorations of said movable member, latching means for holding said lever in source-connecting position, and means effective on arrival of said movable member Yin said initial position for tripping said latching means.

18. In a cumulative maximum demand device having a member movable from an initial position to a position corresponding to the maximum demand for a predetermined interval, a first gear connected for movement in accordance with 'the movement of said movable member, a register having an actuating gear, a lever mov- -able between afirst location and a second location, coupling means controlled by said lever for coupling said two gears when said lever is in its first location and for uncoupling said two gears when said lever is vin its second location, motive means, and transmission means for coupling said motive means to said iirst gear for moving said movable member to its initial position, said transmission means including a releasable coupling engageable only when said lever is in its rst location.

'19. In a cumulative maximum demand device having a member movable from an initial position to aY position corresponding to the maximum demand for a predetermined interval, a first gear connected for movement in accordance with the movement of said movable member, Va register having an actuating gear, a lever movable between a rst location and a second location and biased towards said second position, latching means for holding said lever in its iirst location, means veffective when said movable member is in its initial position for tripping said latching means, coupling means controlled by said lever for coupling said two gears when said lever is in its rst location and for uncoupling said two gears when said Vlever is in its second location, motive means, and transmission means for coupling said motive means to said rst gear for moving said movable member to its initial position, said transmission means including a f releasable coupling engageable only when said lever is in its rst location.

20.'In a cumulative maximum demand device having Aa member ymovable from an initial position to a position corresponding to the maximum demand for a predetermined interval, a first gear connected for movement in accordance with the movement of said movable member, a register having an actuating gear, a lever movable between a rst location and a second location, coupling means controlled by said lever for coupling said rtwo gears when said lever is in its rst location and for uncoupling said two gears when said lever is in itssecond location, motive means, actuating means for moving said 'lever into its first location, and means effective `only when said actuating means is operated in one direction for moving said lever into its rst location and then is operated in a second direction for coupling said motive means to said first gear, the'cou-pling of said motive means to said rst gear being effective for moving said movable member towards its initial position.

21. In a cumulative maximumdemand device having a member movable frcm an initial position to a position corresponding to the maximum demand for a-predetermined interval, a rstgear connected for movement in accordance with the movement of said movable member, a register having an actuating gear, said rst gear and said actuating vgear being mounted for rotation about a common axis, a lever movable between a irst location and a second location, coupling gear means controlled by said lever for coupling said two gears when said lever is in its rst location and for uncoupling said two gears when said lever is in its second location, mot-ive means, and transmission means for lcoupling `said motive means to said first gear for moving said movable member to its initial position,'said transmission means including a releasable coupling engageable only when said lever is in its rst location.

22. In a cumulative maximum demand device having a member movable from an initial position to a position corresponding to the maximum demand for a predetermined interval, a rst'gear connected for movement in accordance with the movement of said movable member, a register having anactuating gear, a lever movable between a first location and a second location, coupling means controlled by said lever for coupling said two gears when said lever is in its first location and for uncoupling said two gears when said lever is in its second location, motivev means, transmission means for coupling said Ymotive means to said rst gear for moving said movable member to its initial position, said transmission means including a releasable coupling, and a second lever pivoted on said first-named lever for controlling said releasable coupling, said second lever being operable :for engaging said releasable coupling only when said rst-named lever is in its irst location.

ROBERT H. LEWIS. PAUL G. ADAMS. 

